The present disclosure generally relates to a spindle motor.
A spindle motor performs a function of rotating a disk to enable an optical pickup which linearly reciprocates in an optical disk drive ODD and a hard disk to read a large amount of data recorded on the disk. The ODDs have been recently developed to stably rotate an optical disk at a high speed.
The ODD includes a spindle motor for rotating an optical disk at a high speed, an optical pickup module for reading out data from a disk rotating at a high speed or recording the data on the disk, and a stepping motor for driving the optical pickup module.
The spindle motor rotating the optical disk at a high speed includes a bearing rotationally supporting a rotation shaft, a bearing housing accommodating the bearing, a stator secured at a periphery of the bearing housing, a rotor rotationally accommodated on the bearing, a base plate fixing the bearing housing and a circuit substrate arranged at an upper surface of the base plate.
A gap is formed between an upper surface of the base plate and the stator according to a conventional spindle motor to disadvantageously introduce foreign objects. In order to reduce the gap formed between the stator and the upper surface of the base plate, the circuit substrate arranged on the upper surface of the base plate is unnecessarily extended to a bottom surface of the stator. If the circuit substrate is extended to between the stator and the base plate, inflow of foreign objects into the base plate and the stator may be reduced to a certain degree. However, a problem occurs in which an area of the high-priced circuit substrate disadvantageously increases to increase a manufacturing cost of the spindle motor.